| /** |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hbase.regionserver; |
| |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.Cell; |
| |
| /** |
| * This interface is used for the tracking and enforcement of Deletes |
| * during the course of a Get or Scan operation. |
| * <p> |
| * This class is utilized through three methods: |
| * <ul><li>{@link #add} when encountering a Delete</li> |
| * <li>{@link #isDeleted} when checking if a Put KeyValue has been deleted</li> |
| * <li>{@link #update} when reaching the end of a StoreFile</li> |
| * </ul> |
| */ |
| @InterfaceAudience.Private |
| public interface DeleteTracker { |
| |
| /** |
| * Add the specified cell to the list of deletes to check against for |
| * this row operation. |
| * <p> |
| * This is called when a Delete is encountered in a StoreFile. |
| * @param cell - the delete cell |
| */ |
| void add(Cell cell); |
| |
| /** |
| * Check if the specified cell buffer has been deleted by a previously |
| * seen delete. |
| * @param cell - current cell to check if deleted by a previously seen delete |
| * @return deleteResult The result tells whether the KeyValue is deleted and why |
| */ |
| DeleteResult isDeleted(Cell cell); |
| |
| /** |
| * @return true if there are no current delete, false otherwise |
| */ |
| boolean isEmpty(); |
| |
| /** |
| * Called at the end of every StoreFile. |
| * <p> |
| * Many optimized implementations of Trackers will require an update at |
| * when the end of each StoreFile is reached. |
| */ |
| void update(); |
| |
| /** |
| * Called between rows. |
| * <p> |
| * This clears everything as if a new DeleteTracker was instantiated. |
| */ |
| void reset(); |
| |
| |
| /** |
| * Return codes for comparison of two Deletes. |
| * <p> |
| * The codes tell the merging function what to do. |
| * <p> |
| * INCLUDE means add the specified Delete to the merged list. |
| * NEXT means move to the next element in the specified list(s). |
| */ |
| enum DeleteCompare { |
| INCLUDE_OLD_NEXT_OLD, |
| INCLUDE_OLD_NEXT_BOTH, |
| INCLUDE_NEW_NEXT_NEW, |
| INCLUDE_NEW_NEXT_BOTH, |
| NEXT_OLD, |
| NEXT_NEW |
| } |
| |
| /** |
| * Returns codes for delete result. |
| * The codes tell the ScanQueryMatcher whether the kv is deleted and why. |
| * Based on the delete result, the ScanQueryMatcher will decide the next |
| * operation |
| */ |
| enum DeleteResult { |
| FAMILY_DELETED, // The KeyValue is deleted by a delete family. |
| FAMILY_VERSION_DELETED, // The KeyValue is deleted by a delete family version. |
| COLUMN_DELETED, // The KeyValue is deleted by a delete column. |
| VERSION_DELETED, // The KeyValue is deleted by a version delete. |
| NOT_DELETED |
| } |
| |
| } |